#### Question

In a regular pentagon ABCDE, Inscribed in a circle; find ratio between angle EDA and angle ADC.

#### Solution

Arc AE subtends ∠AOE at the centre and

∠ADE at the remaining part of the circle.

∴ ∠ADE =` 1/2 xx 72°`

= 36 [central angle is a regular pentagon at O]

∠ADC = ∠ADB + ∠BDC

= 36° + 36° + 72°

∴ ∠ADE : ∠ADC = 36° : 72° = 1: 2

Is there an error in this question or solution?

Solution In a Regular Pentagon Abcde, Inscribed in a Circle; Find Ratio Between Angle Eda and Angle Adc. Concept: Arc and Chord Properties - the Angle that an Arc of a Circle Subtends at the Center is Double that Which It Subtends at Any Point on the Remaining Part of the Circle.